Safety control device



1 Jan- 24 196 R. L. vlcENzl 2,969,078

,SAFETY CONTROL DEVICE Filed May 8, 1957 INVENTOR. Reno L. VlceN zaUnited Sttes Patent O SAFETY CONTROL DEVCE Reno L. Vicenzi, Milwaukee,Wis., assigner to Controls Company of America, Schiller Park, Ill., acorporation of Delaware Filed May 8, 1957, Ser. No. 657,850 9 Claims.(Cl. 137.-66)

This invention relates to a control particularly adapted to use inregulating gas ow to a heating unit having pilot and main burners.

During summer months it is desirable to positively shut down the mainburner of a furnace or the like but the p-ilot flame should bemaintained to keep the furnace dried out. In the past this has been doneby providing a separate plug valve in the main burner gas line or byproviding a switch to break circuit of the solenoid valve regulatingflow -to the main burner. These approaches are somewhat costly and thepresent invention permits the flow to the main burner to be cut off atvery low equipment cost.

The basic object of this invention is to provide a simple, effectivemeans for preventing flow to the main burner.

Another object is to provide for summer shutdown by utilizing to a greatextent the necessary parts of any safe gas control.

ln carrying out this invention a simple interrupter type safety valve isemployed but is modified so the interrupter valve can be locked shutwithout interfering with operation of the safety valve in regulatingflow which is directed only to the pilot with the interrupter valvelocked. Therefore, 100% safe operation is maintained. This simple buteffective concept has broad application and is easily modiiied toembrace switch operation and the like.

Other objects and advantages will be pointed out in, or be apparentfrom, the specification and claims, as will obvious modifications of thesingle embodiment shown in the drawings in which:

Figure 1 is a somewhat schematic view of the present device; and

Figure 2 shows the device with the interrupter valve locked shut and thesafety valve closed.

Referring to the drawings now in detail, it will be seen that only avery simple form of ilow interrupter va'lve body 10 is shown but itshould be understood that this type of construction can be incorporatedin a more complex valve arrangement. Body 10 is provided with inlet 12,outlet 14 to the pilot burner and a main burner outlet 16. Safety valve18 cooperates with seat 20 to regulate flow to both the pilot and mainburners. The valve is carried on stem 22 connected to armature 24 whichis adapted to be held by electromagnet 26 against the bias of spring 28when the thermocouple (not shown) Patented Jan. 24, 1961 spring 40. Asthe stem moves downwardly towards the energizing the electromagnet isheated Iby the pilot flame.

When so held valve 18 will be open to permit flow to both the pilot andthe main burners. This type of construction is, of course, quite old.

Safety mechanisms of this type must be reset and the presentconstruction is of the type broadly classied as a ow interrupter type.With this arrangement the reset stern Sti is pushed downwardly bydepressing cap 32 against the bias of spring 34 so the end of the sterncan act against valve 18. The stern mounts on interrupter valve 36 whichis biased against ange 38 on the stem by seat to block flow to the mainburner and at that time the stem slides axially of the interrupter valveto finally engage valve 18 and push the valve open while resettingarmature 24 to the electromagnet 26. This permits ow to the pilot burnersince pilot burner outlet 14 is located between the safety valve and theinterrupter valve. The pilot burner is now ignited and the heat thereofenergizes the thermocouple to in turn energize the electromagnet toretain armature 24 and hold valve 18 open. If the reset stem 30 isallowed to retract before the electromagnet is suiciently energizedspring 28 will close the safety valve and cut off all the ow. However,if the electromagnet retains Ythe armature then the safety valve willremain open andl movement of the stem 30 outwardly under the inuence ofspring 34 will, of course, cause the stern to pick up the interruptervalve 36 and move it o its seat whereupon ow to the main burner canoccur.

As thus far described the arrangement is essentially that of a basicflow interrupter valve. However, in the present case, a stop mechanismis provided in which the reset cap 32 is provided with an ear 42 on theperiphery of the cap skirt which can be rotated on the stern to engagethe ear under head 44 of pin 46. This prevents full withdrawal of thereset pin 30 so that the pin cannot pick up the interrupter valve 36which is, therefore, held on its seat to prevent flow to the mainburner. lt will be seen from the drawings that the safety Valve 18 isstill fully operative since it can seat without interference from thepin 30.

Now then, it will be appreciated that in normal operation the cap 32 ofthe reset mechanism is normally positioned so ear 42 will not engage theunderside of head 44 on pin 46. At this time the interrupter type resetoperates in the normal way. However, if it is desired to close thefurnace down for summer operation it is necessary only to push in thereset and then turn cap 32 to engage ear 42 with the underside of pinhead 44 so the interrupter valve is held against its seat and flow tothe main burner is cut olf without impairing the safety function of thesafety valve 18 which is now employed only for controlling ow to thepilot burner. It will be seen that the control is completely safe(achieves shut oi if pilot fails) in either form of operation. The onlyparts required over a regular interrupter to provide the summer shutdownfeature are the ear on the push pin and the headed pin.

It will be appreciated that other types of locking mechanisms could besubstituted for the locking mechanism shown in the drawing. Thus, forexample, a pin could be mounted transversely of the push pin 30 andadapted to be received within a slot on the inside of the housing fornormal operation and to span the slot to prevent full withdrawal of thereset pin for the summer shutdown operation. Other types of lockingmechanisms will readily occur to those skilled in the art and it is tobe appreciated that all of such concepts come within this invention.

Similarly, it will be appreciated that there are some types of resetmechanisms where instead of using an interrupter valve such as valve 36a switch is incorporated in circuit with the solenoid valve controllingow to the main burner and operated -by actuation of the reset pin. Thepresent construction is fully adaptable to that type by merelysubstituting a switch for valve 36.

Finally, it should be noted that this concept is applicable to valvesnot of the interrupter type but utilizing rather dilerent structures.One such example is seen in the copending Vicenzi et al. applicationSerial Number 652,427.

It View of the above remarks it will be appreciated that the presentinvention is not to be limited by the disclosure in the drawings but isto be limited only by the scope of the claims.

I claim:

1. A control comprising, a rst control device movable between a rstposition and a second position, a second control device movable betweena rst position and a second position, condition responsive meansrequiring resetting connected to the iirst device for retaining it inits rst position while the response condition obtains and operative tomove the rst device to said second position when the condition does notobtain, reset means operatively connected to the iirst device and to theresponse means for resetting the response means and moving the firstdevice to its first position, means biasing the second device to itssecond position, means for moving the second device to its firstposition upon completion of resetting the response means, and stop meansfor preventing movement of the second device to said first position atany time, said response means being operative after being reset to movethe first device to its rst position regardless of the position of thesecond device.

2. A control device according to claim l in which the iirst device is asafety valve while the second device is an interrupter valve and saidmeans preventing movement of the second device to its first positioncomprises means for locking the interrupter valve in its closedposition.

3. A gas ow control comprising, a valve arrangement including irst andsecond valves movable between ow permitting and how preventingpositions, condition responsive holding means requiring resetting andoperatively connected to the iirst valve at all times to hold it in theflow permitting position when the response condition obtains and to movethe first valve to its flow preventing position when the responsecondition ceases, reset means for resetting the holding means, meansconnecting the second valve and the reset means whereby the second valveis held in the tiow preventing position during the resetting operationand is moved to the flow permitting position upon completion of theresetting, and stop means for preventing movement of the second valve tothe flow permitting position after completion of resetting of theholding means, said stop means being effective only after the resetmeans has moved to a position in which the reset means is unable toaiect peration of the rst valve.

4. A gas flow control according to claim 3 in which the second valve iscarried by the reset means and must be closed before the reset means isoperative to reset the holding means.

5. A fluid ow control device comprising, a pair of valve means,condition responsive means requiring resetting and connected to one ofsaid valve means for retaining said one valve means open in response toa condition and for closing said one valve means when the condition nolonger obtains, reset means for resetting the condition responsive meansand operative to open said one valve means during the resettingoperation, the other of said valve means being operatively connected tothe reset means for movement thereby to its open position uponcompletion of the resetting operation, and means for optionallypreventing movement of said other valve means to its open position, saidpreventing means being operative to prevent movement of said other valvemeans to its open position only after the reset means has moved to aposition in which it is unable to eect movement of said one valve meansto its closed position when said response condition no longer obtains.

6. A uid ow control device comprising, rst and second control membersmoveable between flow preventing and flow permitting positions,thermoelectric safety means including an electromagnet and an armaturenormally occupying retracted positions and moveable to attractedpositions wherein the armature is retained in response to a condition,one of said control members being operatively connected to said safetymeans; reset means for resetting the electromagnet and armature toattracted position and for moving said one of the control members to itsflow permitting position for retention in such position so long as theresponse condition obtains, the safety means acting to move said onecontrol member to its iiow preventing position when the responsecondition does not obtain, means biasing the second control member toits flow preventing position, means operative upon completion of theresetting to move the second control member to its flow permittingposition, and means for overcoming the last named means whereby thesecond control member is retained in its ow preventing position, theoperation of the safety means being unaiected by the position of thesecond control member.

7. A control comprising, rst and second control devices each moveablebetween irst and second positions, means biasing each device to itssecond position, condition responsive means requiring resettingconnected to the first device for retaining it in its iirst positionwhile the response condition obtains, reset means operatively connectedto the iirst device and to the response means and moveable in onedirection for resetting the response means and moving the irst device toits rst position, means operative during motion of the reset means inanother direction upon completion of the resetting of the response meansfor moving the second device to its first position, and means forpreventing movement of the second device to said iirst position at anytime, said iirst device being moveable to its second position at alltimes except during the resetting operation.

8. A gas ow control comprising, a valve body having an inlet connectedto a main burner outlet and a pilot burner outlet, a safety valvecontrolling flow to both outlets, means biasing the safety valve closed,condition responsive means requiring resetting and operatively connectedto the valve to retain it in its open position in response to a controlcondition and to release it for closing movement when the controlcondition no longer obtains, an interrupter valve located downstream ofthe pilot burner outlet for controlling ow to the main burner outlet,means biasing the interrupter valve to its closed position, reset meansmoveable in one direction to open the safety valve and reset thecondition responsive means, means carried by the reset means to engagethe interrupter valve during return movement of the reset means, andmeans operable only after the reset means has returned to a position inwhich it is unable to eiect operation of the safety valve for preventingengagement of the engaging means and the interrupter valve.

9. A control according to claim 8 in which the reset means includes areeiprocable plunger and the preventing means comprises a stop to limitreturn motion of the plunger.

References Cited in the tile of this patent UNITED STATES PATENTS GreatBritain Aug. 15, 1956

